TMK human lifespan

So now we know a normal human lives till around 200 years. This is roughly twice the lifespan of real people. By this logic we need to divide the age of a character to get their equivalent age.
Abigail would be 14~15, Agera 18 and Dylan (r.i.p) about 21 years of age.
But M. still lived 5 times the normal human lifespan for this world..... it must be them arms.